﻿using System;
using System.IO;
using System.Data;
using System.Collections;
using System.Data.OleDb;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace JinYiHelp.ExcelHelp
{
  public  class ExcelHelper
    {
            #region 数据导出至Excel文件
           
            /// <summary>
            /// 将数据导出至Excel文件
            /// </summary>
            /// <param name="Table">DataTable对象</param>
            /// <param name="ExcelFilePath">Excel文件路径</param>
            public static bool OutputToExcel(DataTable Table, string ExcelFilePath)
            {
                if (File.Exists(ExcelFilePath))
                {
                    Console.WriteLine("该文件已经存在！");
                    return false;
                    
                }

                if ((Table.TableName.Trim().Length == 0) || (Table.TableName.ToLower() == "table"))
                {
                    Table.TableName = "Sheet1";
                }

                //数据表的列数
                int ColCount = Table.Columns.Count;

                //用于记数，实例化参数时的序号
                int i = 0;

                //创建参数
                OleDbParameter[] para = new OleDbParameter[ColCount];

                //创建表结构的SQL语句
                string TableStructStr = @"Create Table " + Table.TableName + "(";

                //连接字符串
                string connString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + ExcelFilePath + ";Extended Properties=Excel 8.0;";
                OleDbConnection objConn = new OleDbConnection(connString);

                //创建表结构
                OleDbCommand objCmd = new OleDbCommand();

                //数据类型集合
                ArrayList DataTypeList = new ArrayList();
                DataTypeList.Add("System.Decimal");
                DataTypeList.Add("System.Double");
                DataTypeList.Add("System.Int16");
                DataTypeList.Add("System.Int32");
                DataTypeList.Add("System.Int64");
                DataTypeList.Add("System.Single");

                //遍历数据表的所有列，用于创建表结构
                foreach (DataColumn col in Table.Columns)
                {
                    //如果列属于数字列，则设置该列的数据类型为double
                    if (DataTypeList.IndexOf(col.DataType.ToString()) >= 0)
                    {
                        para[i] = new OleDbParameter("@" + col.ColumnName, OleDbType.Double);
                        objCmd.Parameters.Add(para[i]);

                        //如果是最后一列
                        if (i + 1 == ColCount)
                        {
                            TableStructStr += col.ColumnName + " double)";
                        }
                        else
                        {
                            TableStructStr += col.ColumnName + " double,";
                        }
                    }
                    else
                    {
                        para[i] = new OleDbParameter("@" + col.ColumnName, OleDbType.VarChar);
                        objCmd.Parameters.Add(para[i]);

                        //如果是最后一列
                        if (i + 1 == ColCount)
                        {
                            TableStructStr += col.ColumnName + " varchar)";
                        }
                        else
                        {
                            TableStructStr += col.ColumnName + " varchar,";
                        }
                    }
                    i++;
                }

                //创建Excel文件及文件结构
                try
                {
                    objCmd.Connection = objConn;
                    objCmd.CommandText = TableStructStr;

                    if (objConn.State == ConnectionState.Closed)
                    {
                        objConn.Open();
                    }
                    objCmd.ExecuteNonQuery();
                }
                catch (Exception exp)
                {
                    throw exp;
                }

                //插入记录的SQL语句
                string InsertSql_1 = "Insert into " + Table.TableName + " (";
                string InsertSql_2 = " Values (";
                string InsertSql = "";

                //遍历所有列，用于插入记录，在此创建插入记录的SQL语句
                for (int colID = 0; colID < ColCount; colID++)
                {
                    if (colID + 1 == ColCount)  //最后一列
                    {
                        InsertSql_1 += Table.Columns[colID].ColumnName + ")";
                        InsertSql_2 += "@" + Table.Columns[colID].ColumnName + ")";
                    }
                    else
                    {
                        InsertSql_1 += Table.Columns[colID].ColumnName + ",";
                        InsertSql_2 += "@" + Table.Columns[colID].ColumnName + ",";
                    }
                }

                InsertSql = InsertSql_1 + InsertSql_2;

                //遍历数据表的所有数据行
                for (int rowID = 0; rowID < Table.Rows.Count; rowID++)
                {
                    for (int colID = 0; colID < ColCount; colID++)
                    {
                        if (para[colID].DbType == DbType.Double && Table.Rows[rowID][colID].ToString().Trim() == "")
                        {
                            para[colID].Value = 0;
                        }
                        else
                        {
                            para[colID].Value = Table.Rows[rowID][colID].ToString().Trim();
                        }
                    }
                    try
                    {
                        objCmd.CommandText = InsertSql;
                        objCmd.ExecuteNonQuery();
                    }
                    catch (Exception exp)
                    {
                        string str = exp.Message;
                    }
                }
                try
                {
                    if (objConn.State == ConnectionState.Open)
                    {
                        objConn.Close();
                    }
                }
                catch (Exception exp)
                {
                    throw exp;
                }
                return true;
            }

            /// <summary>
            /// 将数据导出至Excel文件
            /// </summary>
            /// <param name="Table">DataTable对象</param>
            /// <param name="Columns">要导出的数据列集合</param>
            /// <param name="ExcelFilePath">Excel文件路径</param>
            public static bool OutputToExcel(DataTable Table, ArrayList Columns, string ExcelFilePath)
            {
            if (File.Exists(ExcelFilePath))
            {
                Console.WriteLine("该文件已经存在！");
                return false;
                
            }

                //如果数据列数大于表的列数，取数据表的所有列
                if (Columns.Count > Table.Columns.Count)
                {
                    for (int s = Table.Columns.Count + 1; s <= Columns.Count; s++)
                    {
                        Columns.RemoveAt(s);   //移除数据表列数后的所有列
                    }
                }

                //遍历所有的数据列，如果有数据列的数据类型不是 DataColumn，则将它移除
                DataColumn column = new DataColumn();
                for (int j = 0; j < Columns.Count; j++)
                {
                    try
                    {
                        column = (DataColumn)Columns[j];
                    }
                    catch (Exception)
                    {
                        Columns.RemoveAt(j);
                    }
                }
                if ((Table.TableName.Trim().Length == 0) || (Table.TableName.ToLower() == "table"))
                {
                    Table.TableName = "Sheet1";
                }

                //数据表的列数
                int ColCount = Columns.Count;

                //创建参数
                OleDbParameter[] para = new OleDbParameter[ColCount];

                //创建表结构的SQL语句
                string TableStructStr = @"Create Table " + Table.TableName + "(";

                //连接字符串
                string connString = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + ExcelFilePath + ";Extended Properties=Excel 8.0;";
                OleDbConnection objConn = new OleDbConnection(connString);

                //创建表结构
                OleDbCommand objCmd = new OleDbCommand();

                //数据类型集合
                ArrayList DataTypeList = new ArrayList();
                DataTypeList.Add("System.Decimal");
                DataTypeList.Add("System.Double");
                DataTypeList.Add("System.Int16");
                DataTypeList.Add("System.Int32");
                DataTypeList.Add("System.Int64");
                DataTypeList.Add("System.Single");

                DataColumn col = new DataColumn();

                //遍历数据表的所有列，用于创建表结构
                for (int k = 0; k < ColCount; k++)
                {
                    col = (DataColumn)Columns[k];

                    //列的数据类型是数字型
                    if (DataTypeList.IndexOf(col.DataType.ToString().Trim()) >= 0)
                    {
                        para[k] = new OleDbParameter("@" + col.Caption.Trim(), OleDbType.Double);
                        objCmd.Parameters.Add(para[k]);

                        //如果是最后一列
                        if (k + 1 == ColCount)
                        {
                            TableStructStr += col.Caption.Trim() + " Double)";
                        }
                        else
                        {
                            TableStructStr += col.Caption.Trim() + " Double,";
                        }
                    }
                    else
                    {
                        para[k] = new OleDbParameter("@" + col.Caption.Trim(), OleDbType.VarChar);
                        objCmd.Parameters.Add(para[k]);

                        //如果是最后一列
                        if (k + 1 == ColCount)
                        {
                            TableStructStr += col.Caption.Trim() + " VarChar)";
                        }
                        else
                        {
                            TableStructStr += col.Caption.Trim() + " VarChar,";
                        }
                    }
                }

                //创建Excel文件及文件结构
                try
                {
                    objCmd.Connection = objConn;
                    objCmd.CommandText = TableStructStr;

                    if (objConn.State == ConnectionState.Closed)
                    {
                        objConn.Open();
                    }
                    objCmd.ExecuteNonQuery();
                }
                catch (Exception exp)
                {
                    throw exp;
                }

                //插入记录的SQL语句
                string InsertSql_1 = "Insert into " + Table.TableName + " (";
                string InsertSql_2 = " Values (";
                string InsertSql = "";

                //遍历所有列，用于插入记录，在此创建插入记录的SQL语句
                for (int colID = 0; colID < ColCount; colID++)
                {
                    if (colID + 1 == ColCount)  //最后一列
                    {
                        InsertSql_1 += Columns[colID].ToString().Trim() + ")";
                        InsertSql_2 += "@" + Columns[colID].ToString().Trim() + ")";
                    }
                    else
                    {
                        InsertSql_1 += Columns[colID].ToString().Trim() + ",";
                        InsertSql_2 += "@" + Columns[colID].ToString().Trim() + ",";
                    }
                }

                InsertSql = InsertSql_1 + InsertSql_2;

                //遍历数据表的所有数据行
                DataColumn DataCol = new DataColumn();
                for (int rowID = 0; rowID < Table.Rows.Count; rowID++)
                {
                    for (int colID = 0; colID < ColCount; colID++)
                    {
                        //因为列不连续，所以在取得单元格时不能用行列编号，列需得用列的名称
                        DataCol = (DataColumn)Columns[colID];
                        if (para[colID].DbType == DbType.Double && Table.Rows[rowID][DataCol.Caption].ToString().Trim() == "")
                        {
                            para[colID].Value = 0;
                        }
                        else
                        {
                            para[colID].Value = Table.Rows[rowID][DataCol.Caption].ToString().Trim();
                        }
                    }
                    try
                    {
                        objCmd.CommandText = InsertSql;
                        objCmd.ExecuteNonQuery();
                    }
                    catch (Exception exp)
                    {
                        string str = exp.Message;
                    }
                }
                try
                {
                    if (objConn.State == ConnectionState.Open)
                    {
                        objConn.Close();
                    }
                }
                catch (Exception exp)
                {
                    throw exp;
                }
                return true;
            }
            #endregion

            /// <summary>
            /// 获取Excel文件数据表列表
            /// </summary>
            public static ArrayList GetExcelTables(string ExcelFileName)
            {
                DataTable dt = new DataTable();
                ArrayList TablesList = new ArrayList();
                if (File.Exists(ExcelFileName))
                {
                    using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Excel 8.0;Data Source=" + ExcelFileName))
                    {
                        try
                        {
                            conn.Open();
                            dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new object[] { null, null, null, "TABLE" });
                        }
                        catch (Exception exp)
                        {
                            throw exp;
                        }

                        //获取数据表个数
                        int tablecount = dt.Rows.Count;
                        for (int i = 0; i < tablecount; i++)
                        {
                            string tablename = dt.Rows[i][2].ToString().Trim().TrimEnd('$');
                            if (TablesList.IndexOf(tablename) < 0)
                            {
                                TablesList.Add(tablename);
                            }
                        }
                    }
                }
                return TablesList;
            }

            /// <summary>
            /// 将Excel文件导出至DataTable(第一行作为表头)
            /// </summary>
            /// <param name="ExcelFilePath">Excel文件路径</param>
            /// <param name="TableName">数据表名，如果数据表名错误，默认为第一个数据表名</param>
            public static DataTable InputFromExcel(string ExcelFilePath, string TableName)
            {
                if (!File.Exists(ExcelFilePath))
                {
                    throw new Exception("Excel文件不存在！");
                }

                //如果数据表名不存在，则数据表名为Excel文件的第一个数据表
                ArrayList TableList = new ArrayList();
                TableList = GetExcelTables(ExcelFilePath);

                if (TableList.IndexOf(TableName) < 0)
                {
                    TableName = TableList[0].ToString().Trim();
                }

                DataTable table = new DataTable();
                OleDbConnection dbcon = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + ExcelFilePath + ";Extended Properties=Excel 8.0");
                OleDbCommand cmd = new OleDbCommand("select * from [" + TableName + "$]", dbcon);
                OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);

                try
                {
                    if (dbcon.State == ConnectionState.Closed)
                    {
                        dbcon.Open();
                    }
                    adapter.Fill(table);
                }
                catch (Exception exp)
                {
                    throw exp;
                }
                finally
                {
                    if (dbcon.State == ConnectionState.Open)
                    {
                        dbcon.Close();
                    }
                }
                return table;
            }

            /// <summary>
            /// 获取Excel文件指定数据表的数据列表
            /// </summary>
            /// <param name="ExcelFileName">Excel文件名</param>
            /// <param name="TableName">数据表名</param>
            public static ArrayList GetExcelTableColumns(string ExcelFileName, string TableName)
            {
                DataTable dt = new DataTable();
                ArrayList ColsList = new ArrayList();
                if (File.Exists(ExcelFileName))
                {
                    using (OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Extended Properties=Excel 8.0;Data Source=" + ExcelFileName))
                    {
                        conn.Open();
                        dt = conn.GetOleDbSchemaTable(OleDbSchemaGuid.Columns, new object[] { null, null, TableName, null });

                        //获取列个数
                        int colcount = dt.Rows.Count;
                        for (int i = 0; i < colcount; i++)
                        {
                            string colname = dt.Rows[i]["Column_Name"].ToString().Trim();
                            ColsList.Add(colname);
                        }
                    }
                }
                return ColsList;
            }

        }
}
